Usage
  • 92 views
  • 307 downloads

A study of the colloidal stability of mixed abrasive slurries of silica and ceria nanoparticles for chemical mechanical polishing

  • Author / Creator
    Lin, Fangjian
  • Slurry stability is an important factor in Chemical Mechanical Polishing (CMP) efficiency. However, few studies have been done in this respect. In settling tests at pH 4, adding various amounts of ceria to colloidal silica slurries was shown to change the stability of the resulted mixed abrasive slurries (5 wt% of silica). Within a range of ceria-to-silica weight ratios, known as the transition range, the mixed abrasive slurries were observed to be unstable. A mathematical estimation based on zero net surface charge was proposed. The modification of particle surface charges through the attachment of positively charged ceria particles to negatively charged silica particles made the mixed slurries unstable. TEM images confirmed such attachments at pH 4. Compared to the slurries containing a single kind of particle, such mixed abrasive slurries were more effective in the CMP of PECVD oxide under the same conditions.

  • Subjects / Keywords
  • Graduation date
    2011-11
  • Type of Item
    Thesis
  • Degree
    Master of Science
  • DOI
    https://doi.org/10.7939/R3967C
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
    English
  • Institution
    University of Alberta
  • Degree level
    Master's
  • Department
    • Department of Chemical and Materials Engineering
  • Supervisor / co-supervisor and their department(s)
    • Xu, Zhenghe (Chemical and Materials Engineering)
    • Cadien, Ken (Chemical and Materials Engineering)
  • Examining committee members and their departments
    • Liu, Qingxia (Chemical and Materials Engineering)
    • Xu, Zhenghe (Chemical and Materials Engineering)
    • Sit, Jeremy (Electrical and Computer Engineering)
    • Cadien, Ken (Chemical and Materials Engineering)